Shengang interchange on National highway No.4 opened to traffic with only southern ramp-1, ramp-3, loop-6 and loop-8. Main Object of the project is to improve the function of Shengang interchange by adding new northern ramp-2, ramp4, ramp-5, ramp-7.The improvement works can provide Shengang District and Houli District with convenient transportation service to connect National highway No.4.